Heretofore, it has been common practice to provide screens or shades for windows to prevent the infrared energy of the sun from entering the room and to militate against the loss of heat energy through the windowpane in cold weather. However, although these efforts have helped, they have fallen short of achieving any degree of efficiency, due to a large extent to the escape or leakage of air at the side edge portions of these screens. The body of the screens affords a good barrier for air flow, but the sides are open to relatively free flow and, as a result, a large loss of energy occurs.